Posted
by
Soulskillon Tuesday June 25, 2013 @03:01PM
from the see-how-the-orbit,-see-how-they-orbit dept.

astroengine writes "Gliese 667C is a well-studied star lying only 22 light-years from Earth in the constellation of Scorpius, but it appears to have been hiding a pretty significant secret. The star has at least six exoplanets in orbit, three of which orbit within the star's "habitable zone" — the region surrounding a star that's not too hot and not too cold for liquid water to exist on their surfaces. Astronomers already knew that Gliese 667C had three worlds in orbit, one in the star's habitable zone, but the finding of three more exoplanets, two of which are also in the habitable zone is a huge discovery. Finding one small planet in a star's habitable zone is exciting, but finding three is historic. 'The number of potentially habitable planets in our galaxy is much greater if we can expect to find several of them around each low-mass star — instead of looking at ten stars to look for a single potentially habitable planet, we now know we can look at just one star and find several of them,' said Rory Barnes, of the University of Washington, co-author of the study, in an ESO press release Tuesday (June 25)."

if you accelerate constantly a 1g for 11 light years and then decelerate at 1g fo 11 light years it takes 9 years to get there in your rest frame. in earth frame time this is much longer so you cant just come back in 18 earth years, but you can come back in 18 of your own.

By all means use a better propulsion system. Ion jet rockets probably are the best currently buildable. But you will still need to limit your top velocity, or you will be damaged by interstellar dust particles. Grain of sand is probably the worst to deal with. Too small to see in time to dodge, and too large to shield against. Of course, if you were going faster even smaller particles would be more dangerous. My guess is that this factor would limit you to 0.1c, but that's a wild guess. I could easily be off by a factor of 10 in either direction.

Perhaps it would help if the vehicle were preceeded by a balloon filled with ice (water). But that's rather hard to see through, and hard to manuver if you need to dodge something too large.

And the more complex you make things, the more likely it is you'll experience a breakdown along the way.

Still, one thing that we really need to do is send one of these things with an on-board telescope of moderate power. Have the ship spin slowly, and stream the pictures back to earth. You don't need a fast transmission rate as one picture/week at any given angle should suffice, and half or a quarter of that would be acceptable. But this would give us a LONG parallax line. (N.B.: I'm not talking about something with high resolution, or infrared capability, and any other exotic capability. I'm presuming that the pictures would be stitched together with software after being received. So the buffer would only need to hold one image at a time.)

Now it's true that this wouldn't show much about the target system within our lifetimes, but it might show us a great deal about things off to the side. And it would test many of our estimates of distance (which, to be frank, rest on reasonable but not directly testable assumptions). That said, even this would only directly test distances about near bodies. It's not a long enough baseline to directly test Cephid variable distances, except a few. And I'm only expecting it to verify what is already known. But it would allow us to test our model of the local 3d starspace against direct imagery.

Though if you are de/accelerating the whole time, 50/50, then you'll only be hitting the peak speed near the middle part of the journey. Also, after the half way point you are facing ass (rocket) forward: hopefully the output from the thrusters could be designed to help deflect small particles in the way. So it's only the 35-50% mark to worry about.

Kirk: Scotty, the Penis Enlargement ads are overwhelming the system, we need more power!Scotty: Captain, I'm giving you all we've got! We even added Viagra to the Di-lithium crystals but now they're poking holes in the containment vessel! Oh, If only someone had not answered that ad for Hot Green Babes!Kirk: Err... yes... a mystery...

There are many exoplanet claims with both the transit method and the Doppler method. What I'd like to see is use them in the same systems to see whether they yield the same results. Right now, these are only predictions, not discoveries, and they are hard to verify.

If a system can be checked with the transit AND the doppler method, you can be asured they use both. However 90% of the systems where you can use the doppler method can not be examined via the transit method. (Wrong angle of the eclipse)They are discoveries. Just because you don't grasp the science makes them not "just predictions".

One problem that has not be determined is how do planets deal with the inherent variability with Red Dwarf stars. There are many, many more red dwarfs than other types of stars and their expected life expectancy is longer the estimated end of the universe. But their small nature makes their energy output more variable than a star like our sun.Does the long life, and greater number of Red Dwarfs significantly boost the drake equation? Does the variable energy output reduce the drake equation?

One problem that has not be determined is how do planets deal with the inherent variability with Red Dwarf stars.

What problem? The planets don't care one bit.

Does the long life, and greater number of Red Dwarfs significantly boost the drake equation? Does the variable energy output reduce the drake equation?

It's all rather academic, since plausible values for the DE cover such a wide range that you can reasonably make it come out with pretty much any answer you want. AIUI it was never really meant to put to practical use, and is more of a contemplative notion.

There's plenty of data both pro and con about sending a probe to explore and the timeline necessary. Has anyone ever thought about seeing if perhaps another race has sent a probe at us? And if so, how would we spot it?

perhaps another race has sent a probe at us? And if so, how would we spot it?

Most likely the probe would contain simple life forms which would try to blend in with society by assuming places of privileged power. The kind of power to pass legislation or create policies to give them better leverage over the populace as a whole.

It would not be difficult to spot, however it would be difficult to extricate them once they become resident as they would almost certainly ascertain some control over local and national media in order to sway public opinion in places where rhetoric and ignorance can easily give them political footholds in which to extend their residence.

A probe would probably be meant for observation, not communication since it's so much easier to just boost the signal if there's someone answering at the other end. I think we'd already know if there was a probe in orbit, if it's in transit or just doing a fly-by it'd be a silent black speck of dust we'd have no chance of detecting.

If it's here and it wants to be spotted it would have announced itself by now. If it doesn't want to be spotted we don't have any realistic hope of spotting it. Keep in mind, anyone out there with routine interstellar travel of any kind, even just with automated drones, is more than likely to be hundreds or at least tens of thousands of years ahead of us technologically.

That said, it's always possible that the machinery only wakes up every so often. If it only sticks it head out to look around every 1000

I'm not sure what difference this makes to the actual habitability of the planets, but all of these are tidally locked. That is, the same part of the planet is always facing the star (and thus baked) while the same part faces empty space (and thus freezes). A thick atmosphere might transport heat and make things more uniform, but none of these are what one would naively think of as "habitable". In fact, all planets in the "habitable" zone of such small stars are going to be tidally locked. Wikipedia actually has a nice summary of the problem of tidal locking in small stars [wikipedia.org].

Well, they're all much bigger and closer than Mercury, which would amplify the effects of tidal drag. Mercury avoids full locking by having a large eccentricity. None of the planets in the habitable zone (c,e,f) have substantial measured eccentricity, but the uncertainty is large enough that it might be possible for them to get into a 3:2 resonance. Even in a 3:2, the planet would still face the star for weeks at a time; the resulting temperature fluctuations might actually be more inhospitable than full lo

They are likely habitable in the same way both Mars and Venus are habitable.

We most likely would need to provide our own self-enclosed biosphere, but that is not completely unreasonable.

The key thing is temperature. Mercury is 400'C during the day. Uranus is -150'C during the day. In either case the travelers will need to continuously heat or cool their biosphere using a lot of energy. Trying to keep the biosphere warm during interstellar travel will be an issue since interstellar space is around -260C ac

Given that the only solar system we have even partially explored has at least one potentially habitable planet, why is the constant assumption made that te vast majority of other systems are entirely uninhabitable? Are we really THAT arrogant to think our system is so unique? Based on the evidence in our sample size of one, surely the logical assumption would be that there are plenty of other similar systems?

Why so? In context of just how freakin' big a galaxy or the entire universe is, 22 light years is pretty damned close. The Milky-way alone is > 100,000 light years across.

Not even 25 years ago the prevailing belief was that there wouldn't be that many stars with planets, and now we're finding them pretty much constantly.

One of the terms of Drake's equation is how many stars have planets, and that proportion has been steadily climbing.

So if we're finding this many planets in an astronomically-relative 'nearby', then throughout the rest of the galaxy we have to assume there's just vast amounts of them. Start factoring in the sheer number of galaxies, and even if we'll never meet them, it seems probable that somewhere else would likely have evolved life by now.

I think in the context of the Fermi Paradox finding lots of habitable planets is _bad_ news because it invites the question "so where the hell is all the intelligent life on all these habitable planets" the aswers to that question indicate a term in the drake equation is close to zero, hopefully it isn't the term that indicates the length of time a technological civilization exists....

The most evil sin all over the universe is: man made self replicating machines.

No sane race ever will do that: crafting self replicating machines and letting them lose on the universe.

In the time spans we are talking about: all things you could imagine will go wrong with "replicators". You don't need to read SF to grasp that. At Fermis times no one really thought that out. So his idea is sticking Round as "paradoxon".

I don't think sending self replicating machines would be any more "evil" than sending the self-replicating people that would design them. With a machine you could at least tell it not to wipe out an indig population in an conflict over mutual survivability. You can't expect the current model of humans to do that.

Self replicating machines don't have to be intelligent. Even if they only replicate some kind of marker or beacon to plant as they go. The only way to get ahead of the sheer numbers is to spend time planting seeds and signposts with directions to the other habitable planets. Give races something to shoot for and see if they show up.

I think in the context of the Fermi Paradox finding lots of habitable planets is _bad_ news because it invites the question "so where the hell is all the intelligent life on all these habitable planets"

I rather liked the sci-fi "Fermi Answer" given in Ian Douglas's Heritage/Legacy/Inheritance trilogies: a xenophobic race with a massive Darwinian survival complex decimates every other species that gets close to star travel technology and literally bombards them back into the stone age.

Or perhaps even more likely there's just nothing to detect out there because their "indistinguishable from magic" technology doesn't operate in ways we can detect and all of their EMF shells from bygone eras passed us long ag

And how important was the moon? Some arguments have held that not only the existence of the moon, but the way that it was captured is crucial. (Note that it stabilizes the Earth's axial tilt.)

So, while I find the Fermi Paradox troubling, I don't find it insoluble.

Interesting point. But from a sample of one, one cannot do science. As the planet formation models from before the exoplanet discoveries show, one cannot do viable science based on a sample of one.

Here is how it will work: we will be able to detect spectra of planets within the next 50 years. Based on that, live will be found on many, few, or none. Based on that the models will be adapted, and all nerds on/. in 2060 will fail to understand how we in 2013 did not see how it all really worked, as it's so o

It has to be the timespan of technological civilization. For all we know, there should be no proper civilisation on Earth in few hundred years. Tragedy of the commons [wikipedia.org] will make sure of that. It makes sense for everybody to exploit Earth in short term instead of trying to branch out to space in any real way. And when at some point it will be obvious that it doesn't scale, there will be not enough free/cheap resources available to make that jump. And then big asteriod will appear...That is, if we don't nuke o

Bullshit, you didn't even get your numbers right with that hyperbole. Orders of magnitude are tough, but not entirely unworkable.

Mars is 22 light MINUTES away, and we can get there reasonable well if we had a mind to.

If you can get up to a decent fraction of the speed of light, energetically very expensive I'll grant you, a ship could get to one of these worlds in 100 years or so. That's a long time, but it's not so long as to be considered infinite or unworkable. If you take the point of view that's it poi

100 years of travel for 22 light years away.That's 50 years of acceleration and 50 years of deceleration to travel 22 light years.So you have to accelerate for 50 years and travel 11 light years in the process.

What's the calculated acceleration?

22 light years is 208,200,000,000,000 km.

Average speed to get there in 100 years is 208,200,000,000,000 km divided by 3,153,600,000 seconds, that's 66019.8 km/s. You need to reach that speed in 25 years of acceleration. That's 0.08 m/square second. Easily achievable, provided you don't have to carry half of Earth's mass in fuel. I think even ionic drives can get that sort of acceleration.

Ideally, for a human crew, the ship should alternate acceleration and deceleration so that the perceived gravity is always at 1G. Otherwise, you would accelerate for 1 year, then spend 4 years in zero gravity, then decelerate for 1 year at 1G, which is highly NOT recommended.

Right now it doesn't matter if it were 1.5 light seconds away. We can't get there. It may as well be in another universe.

1.5 light seconds is roughly the distance to the moon. If we had another Earth like planet that close (assuming a somehow stable orbit and ignoring geological and evolutionary impact) you could be vacationing there right now.

There are no humans on the Moon because there's nothing to do on the Moon. There are only so many kilos of regloith you can ferry back and rounds of low gravity golf you can play before there's no point spending the billions to go back. If and when someone thinks up a useful reason to go back to the moon (e.g., a way station for missions to further afield) then I'm sure we'll be back.

If the Moon were an Earth-like world, I'm sure there would be a McDonalds serving Moon Burgers up there by now.

Yes, it should also be noted that we've put no humans on the moon but NASA, ESA, Japan, India, China have all had missions to the moon since and Russia is also planning new missions after they stopped the Luna program in 1976. Mostly what we lack is a compelling reason to send people, it's been done and even repeated a few times so it's a bit like after the first 10 people had been on Mount Everest there's not really much to be proven that we could climb it again. I'd say go straight for Mars, break some ne

Right now it doesn't matter if it were 1.5 light seconds away. We can't get there.

Ummm, the moon is 1.5 light seconds [ucsd.edu] away, and Mars is 4 light minutes away. We can, and have, send stuff to both of those, so 1.5 light seconds isn't this intractable distance you think it is... if you were walking it would essentially be infinitely far away. But with rockets from the 60's it was more like a few days.

I'm not suggesting we're going to reach these any time soon, but you have to remember that relative to the

Right now it doesn't matter if it were 1.5 light seconds away. We can't get there. It may as well be in another universe. By the time we can conveniently travel that far, the whole concept of distance will be meaningless. For the sake of argument, yes, 22 light years is closer than 13 billion, but for now, in practical terms, the distance is infinite. If you already bought your ticket, I would suggest you ask for a refund.

22 years means you can send a message and get a response in your lifetime.

But even in space "nearby" is relative. We can reach Mars in a reasonable amount of time, using technology that's the space equivalent of "walking". Reaching even the nearest star is a whole 'nother story. Something else needs to be invented in order to achieve that. Or as someone smarter than I once said:

“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.”

Maybe not today. But 22 light years is pretty close in galactit terms. Even at half the speed of light you can get there in less than a lifetime. Technology tends to advance forward you know. 150 years ago the thought of getting from N.Y to London in 8 hours was the stuff of fantasy. Today its an everyday thing.

150 years ago the thought of getting from N.Y to London in 8 hours was the stuff of fantasy. Today its an everyday thing.

Yeah, but 11 years ago getting from NY to London in less than 4 hours was an everyday thing (if pricier than other flights). Now it's unheard of. The only planes in service that have the speed and range don't regularly make that kind of trip and they don't take passengers. Modern enthusiasm for advances in technology seems to be limited mostly to whatever the latest smartphone is. Also, the people clamouring for those more advanced smartphones also typically have no clue whatsoever about the actual tech specs of them and are typically just being led around by the nose by marketing. Some of us are very pessimistic about the future of real technological development, at least in the short term.

Um, yes, the industrial revolution is certainly waning. But we've experienced the digital revolution (computers) and the information revolution (the Internet) since then. The Renaissance before that and the agriculture revolution, and that thing where they invented tools from rocks were all similar "big changes" that are still having ramification but have more or less played themselves out. The rate of revolutions has increased so much that many don't see the difference between the digital one and the infor

Modern enthusiasm for advances in technology seems to be limited mostly to whatever the latest smartphone is. Also, the people clamouring for those more advanced smartphones also typically have no clue whatsoever about the actual tech specs of them and are typically just being led around by the nose by marketing.

Or, alternately, modern enthusiasm for technology is directed towards products that can be profitably mass-produced and are within the financial means of the average middle-class consumer. The Concorde was both expensive and money-losing, and the side effects (sonic boom) were more than most people wanted to deal with. (Although I sometimes wish we could use the same logic to ban Bluetooth headsets.)

Unfortunately there are lots of technologies like this, where the know-how and manufacturing capability exists, but the economics and other practical aspects make it unsustainable. I don't think it reflects negatively on modern consumers that they aren't willing to support huge, expensive projects like this, or the International Space Station, etc., simply because technology enthusiasts think they look cool. Having been on intercontinental flights in both directions in the last year, I would love if I could cut the flight times in half. But neither my budget nor my employer's budget would allow me to take the Concorde if it were still in flight, so I don't know why I should be excited about that idea, any more than I'm excited by the availability of fully-reclining seats.

But we as a species are still quite capable of it. Concorde was basically a passenger jet with military spec engines; expensive as hell and incredibly noisy, never exactly a great commercial idea. Basically just another penis-waving contest for the British and French governments. Both the engines and the technology to make the vehicles are still available (and massively improved), it's just there's less appetite for intra-governmental penis waving than there was a few decades ago.

Technology continues to march onwards, and I'm sure supersonic passenger flights will return as soon as the technology reaches a point where it is commercially viable. Just because people prefer to spend their money on pocket-sized super-computers (by the standards of the date when Concorde first flew) than marginally faster trans-Atlantic travel, doesn't mean the world is entering a technological dark age. Quite the reverse, in my opinion.

We do have massively improved steam engine technology; do you think that applications where steam is still used are still using technology from the 19th century? Steam turbines are THE key technology in the vast majority of electricity-generating power plants in use today. All that happened there was that new and better technology supplanted it in the "vehicle power" space.

In the space travel field, we're massively more advanced than we were a few decades ago. We have deep space vehicles with ION engines. W

Yeah, but 11 years ago getting from NY to London in less than 4 hours was an everyday thing (if pricier than other flights). Now it's unheard of.

Yes but it was sort of like the pony express shutting down their rush service because the telegraph arrived, maybe that sucks if you wanted to send a package but for the 95% that wanted to send a letter the telegraph was faster and better. Not every aspect of every old service is going to be preserved by the new ones, there will always be some regressions in the overall picture. Even though we're making incremental improvements I doubt we'll see any revolutionary changes in things like jet propulsion, internal combustion, gas turbines and whatnot - it's just minor tweaks to squeeze more efficiency out of it.

The overwhelming number of changes I expect is for things to get smaller, smarter and for more and more things to go electronically rather than physically and applying brute force. Maybe you get another 5 mph on the interstate but the main difference is an AI that drives itself. My dream of "real technological development" would be things like having nanobots to destroy bacteria, viruses, toxins, cancer cells, cure genetic diseases and prevent aging on the cell level. In the future maybe we all have personal assistants like only the rich have today, only they're robotic. It couldn't be done today because to have servants somebody would have to be the servants, but we could all have a robot the way we all have cell phones.

I'm not going to bash the system we have today, I can go down to the grocery store and buy a finished meal, pop it in the microwave and put the dishes in the dishwasher but it certainly could be taken to the next level where I just tell a robot I'd like spaghetti bolognese today and it'd shop, cook like a professional chef, serve and clear the tables when I'm done. Having a washing machine and a dryer is also rather relaxed, but again being able to throw dirty clothes in the bin and have them sorted, washed, dried, ironed if applicable and put back in the closest by themselves would be even better. Roombas and electronic lawn mowers are just a shadow of what robot housekeepers and gardeners could be. In short, even if I don't see flying cars on the horizon I see plenty things that could make life in 2013 seem rather primitive compared to 100 years from now.

It took us 200 years to increase normal-ish transport speeds from 5mph to 500mph. (Though bulk transport is still more like 30mph.)

We've got a LOT of technology to develop if we want to increase normal-ish transport speeds from 500mph to 1/2 light speed.

It's just about a million times faster than current tech. Even if you assume we get 100x speedup every 200 years, that's another 600 years of tech, though of course I concede that development doesn't need to be 100x every 200 years.

"Even" at 0.5C? You'll need to travel closer to light speed and be able to accelerate at a pretty spanky rate to average that speed. Getting a manned ship to 0.1C with a reasonable acceleration might be hard but doable with next-century tech, but anything more is rather far fetched unless there is some fundamental breakthrough in energy generation, propulsion or physics in general (warp drives or wormholes). Hey, I'm hoping to see this happen just as much as the next guy, but it's not looking good.

Yeah, but if we send a radio message now there is a good 0.000000000000000000000000000000000000001% chance an intelligent civilization that has developed on one of those planets will get it and we will have a response 44 years later. We should therefore earmark billions of dollars for this work and get right on it!

You've made a serious mathematical or other error in your calculation - wow. It's not a 0.000000000000000000000000000000000000001%, it's actually a 0.000000000000000000000000000000000001% chance!! Maybe you miscounted the number of intelligent civilizations?

Contrary to popular belief, no government funds are allocated for its SETI searches

True as of 1995, when the government withdrew support. Not true for many years before that. Personally I think we have plenty enough issues to deal with at the moment that we should keep it that way for now. My point is this article is an "interesting factoid" but to all but a small minority of astrophysicists and enthusiasts is not exactly "historic"...

The problem is, we don't even have space shuttles any more. We're technologically regressing as far as air and space go. Still, if we ever manage to get our act together well enough to actually build something like a generation ship, 22 light years away is pretty close, relatively speaking.

That's true if you think the government's "space program" is the measure of human progress. That's what you get for pinning your hopes and dreams to a bureaucracy funded by money stolen from people at gun-point.

The private space industry, on the other hand, is growing and succeeding at quite an optimistic rate, relative to what most people though was possible 10-15 years ago.

Still, if we ever manage to get our act together well enough to actually build something like a generation ship, 22 light years away is pretty close, relatively speaking.

Voyager has been underway for 36 years and is less than 0.002 light years from earth so it's 10,000+ generations away unless we can go much, much faster. And the concept of generation ships is exactly the opposite, they're massive constructions big enough to sustain a civilization that move very slowly between stars. If we send "humans" I expect it'll be frozen embryos or electronic DNA sequences to be reconstructed on site on a massive rocket ship that'll still take hundreds of years. A light year sounds s

Voyager has been underway for 36 years and is less than 0.002 light years from earth so it's 10,000+ generations away unless we can go much, much faster

Ion engines have been demonstrated to work. Solar sails may also be practical for acceleration in the inner solar system. Accelerating at a very conservative one ten/thousandth of standard gravity, a craft using some such constant acceleration system would be going faster than Voyager 1 in less than 7 months even without a gravity assist. After accelerating as long as Voyager has been, it would be travelling more than 60 times as fast relative to Earth. That would make for a trip of about 6500 years. That's

While seemingly true, this statement is misleading. Having found 3 habitable planets around a single star, it does not follow that all stars have 3 habitable planets. Or even that any other star has 3 habitable planets. I really hope this was just a statement made out of context...otherwise...it just makes me sad.

The point is that planets in the habitable zone are clearly not so rare (either that or we've gotten really, really lucky looking for them). I agree that it does not follow that all stars have three habitable planets. However it does make the odds vanishingly small that no other star has three habitable zone planets.

The solar system called "Sol" also has three planets in the habitable zone. Besides Earth a second one, Mars, was likely once habitable. Venus for some reason got a veyr dense very CO2 heavy atmosphere. With less CO2 it likely would harbor life.

how would we know if these were uninhabited or not? coming will be systems that can analyze the atmosphere of these planets and look for signs of free oxygen, products of life, and products of civilization. it's an awesome time to be alive!